Buch of quickies:

• First, I'm moving from livejournal to blogger. Mainly because blogger allows me to email pictures/videos from my cellphone and automatically converts them to blog entries. To avoid spamming planet with unnecessary entries, only postings tagged with "Debian" be syndicated to p.d.o.
  
• Was invited to UDS and Prague. Quite different from conferences where I've been before (debconf, FOSDEM). Less time spent with one person presenting and rest of room listen, more time people discussing the topic of session. Atleast this was the case in the Mobile track I mostly followed.
  
• Testing scripts now consider Armel a Release architecture. \o/. The armel debian-installer should also be part of debian-installer beta2 really soon(tm) . Only getting testing-security running properly is tricky at the moment...
• fuck I'm old now.
  

Many people in planet are talking about debconf8, the expensive travel fares, the lack of sponsors, and all that stuff. Here's a different POV.

---

I don't live neither in Europe, nor in Asia, I live in Mexico. The travel fares are still too high, and the situation is even worst if you are a student, like me.
When Debconf8 was finally announced to be taking place in Argentina I though it would be my chance to go my first Debconf, now I don't.

From the very beginning I marked the travel funds checkbox but never entered an amount of money as prices were going higher every two days or so. And when the deadline was announced I just made sure it was marked, as I was expecting some kind of 'please enter the prices now' email before the requests were processed.

Now I see how mistaken I was, and with the current travel fare around 28 000 MXN there is definitely no way I am going to debconf8.

Call it lack of time, lack of sponsors, lack of whatever; IMHO something should be done about this, and probably the procedures explained a little further for those who have never attended a Debconf.
Please note that I am not blaming anyone, as I know that the debconf8 team has been working hard to get things working, but there are things that are out of their hands.

During the last 4 days, I didn't read Planet. So I started an interesting exercise and wanted to comment very briefly on a few entries I just read quickly to catch up. My Planet premium, so to say..

• (not Planet related...I read that on NASA mailing lists...some of which I'm subscribed since 1988) NASA's Phoenix lander successfully landed on Mars. This is actually the first successful soft landing on Mars since 1976 (recent landings were hard ones, with airbags....or failures). This stunning picture shows the spacecraft with its parachute during its descent on Mars. It was taken by the HiRISE camera of Mars Reconnaissance Orbiter. The very first time a spacecraft photographs another one while it's landing. Amazing, right?
• Marga and the Spanish keymap: I can't disagree with your comments, Marga. Still, that's a though issue: changing the behaviour of a keymap that's used by millions of users is not a trivial change. OTOH, you're right and that tilde should be dead, indeed. I think there is barely no other option than a fork, here: have both keymaps, one with asciitilde and another one with dead_tilde on the same key combination and let users choose. That keymap should be named "es-standard" to avoid changing the existing "es".
• John Goerzen biking to work: John is among the people I never met but who I know I share ideas and vision of life with. So, seeing him comment on alternative ways to commute to/back work is a pleasure for me (alternative transportation systems with the goal of abandoning the heresy of individual cars is part of my hobbies....while I still don't always apply these principles myself). And, well, seeing someone writing that this is still possible in the flat MidWest of the country that contributes the most to climate change is a relief for me: change can happen.
• Joey reads USENET again. Long time since I last read news... In the past I used to have my own feed, through UUCP. I still receive a lot of my mails by UUCP, though (bubulle@kheops.frmug.org comes this way)
• Pollocks were in Europe. Andrew is another of these people I feel like having connections with while we never met. Next time, plan a stop in Bubulle Hotel and visit Paris, Andrew.
• Dirk mentioned Bike the Drive, which I assume to be a bike-related event in Chicago... Yet another occasion to see there's still some hope for alternatives to cars in the US of A...
• Kartik is back home in Mumbai after some months working in Bangalore (and not enjoying it). I'm happy for him that he can be again with his family.
• Ganneff also bikes. Of course, he does it the geek way. Would you have guessed? Joerg, are you ready for the DebConf daily running tour which I plan to do in Mar del Plata?
• Manoj is the last Emacs user, along with /me
• Jaldhar who I have much respect for in the project, still supports the US republican party, the most conservative party in the so-called western world. It is still completely out of my understanding how FLOSS "spirit" can fit with this (the same stands for the political stance of Eric "Gun" Raymond, indeed). Mysteries...
• Lucas wonders how to find cheap flights. Voyages SNCF (aka Expedia), the online travel agency of the French railway company, always gets my preference. Yes, French *railway*.
• MJ also posts about biking. I have to mention that easy bike-on-demande systems in cities are one of the best ways to develop this. Barcelona's system seems pretty cool. Paris' Velib is amazing and so is the system in Lyon (who initiated the movement in France). All this is something I personnally follow pretty closely (I'm a addicted reader of the French professionnal magazine named "Ville et Transport", "Town and Transportation") in the hope it also develops in my Suburbia.
• Too many technical issues on Planet. I can't follow..:-)

England swings like a pendulum do! There's another fuel price protest and the coverage in the London press is pretty biased, with occasional balanced reports and very rare dissenting opinion. One of the favourite whines on news-and-nutters phone-ins is "waah, I live in a village, I need my car". While that's true for some people, most villagers could switch to bicycles for many journeys without problems. At the moment, the biggest problem with cycling to town is the number of cars on the small lanes, followed by the number of potholes. Switching to cycling or walking will have a triple benefit: fewer cars on the road will free up space for cycling, wear the roads out less and reduce fuel demand (so petrol should become cheaper for those who really need it). Over the last few days, I've been happy to read Bike The Drive 2008 [Dirk Eddelbuettel], Mountainbike, By Joerg Jaspert and How to Start Bicycling to Work, by John Goerzen. A couple of tweaks to that last one: in England, I don't think that a cycling helmet is necessary. I've not worn one for the last few months (it went mouldy after a rain storm) - I find I can hear traffic better and many drivers seem to give me more room on the road. I wonder if helmet-wearing "dehumanises" cyclists to drivers? The safety data seems rather confused, but it's a personal choice. If you feel safer with a helmet, wear one. I also wear ordinary business or casual clothes, relying on a good quality commuter saddle rather than cycling shorts. I suspect that drivers here are developing a sort of blindness to the "screaming yellow" hi-vis jackets, so I don't wear those - but sometimes I wear hi-vis reflective armbands if I'm wearing black in the dark. I agree completely with the comments on that page about being predictable, Cateye lights and pannier bags. Finally, Bike Week 2008 starts on 14 June, which would be an ideal time to try a group ride - or just get a free breakfast for cycling into town.

Michelle’s post‡ today on laptops in the classroom (in a similar vein to this article I read last month on the suggestion of Glenn Reynolds) reminded me that I had a few items from the past few weeks still in my Google Reader queue of “things to blog about” related to Margaret Soltan’s continuing crusade against the use of PowerPoint* and its ilk, and specifically Timothy Burke’s partial rebuttal:

What’s the difference between bad usage of PowerPoint in lectures and bad lectures that involve hand-outs, overhead transparencies and writing on the chalkboard? Are we just complaining about old wine in new bottles here? Is the real culprit professorial droning at classrooms of 200+ students followed by recite-repeat-and-forget examinations? I think it’s at least plausible that the technology is just giving us a new reason to pay attention to a pedagogy whose effectiveness has been suspect for two generations.

I dare say I’m among the last doctoral students who was “trained”—and I use that word loosely—to teach prior to the widespread use of PowerPoint. Four years of full-time in-classroom experience, mostly with small lectures and seminars, has brought me basically to agreement with Burke on this point—complaints about PowerPoint essentially boil down to complaints about either instructional laziness or the whole nature of lecturing, or as a Burke commenter puts it, ”[e]xactly how does one teach even 80† students at once without succumbing to passive data transfer?” The non-use of PowerPoint or some other form of instructional technology seems to me to be a luxury confined to those who only teach small seminars and graduate students, and while my personal career aspirations lean in that direction the reality is that I’m several years away (in terms of research productivity) from being there—if I ever get there. Burke in his comments hits the nail on the head, I think, when it comes to any sort of visual presentation in class:

It seems to me that the absolutely key thing is to avoid speaking the slides literally. They’re best as definitions, key concepts, images: the kind of thing you’d stop your flow of lecturing to write on the chalkboard. They’re not the lecture itself.

I think there are three useful aspects to a lecture: what you put on the board (or slides), what you say, and the general outline. If you’re preparing a handout or something to stick on Blackboard for students, the outline or outline-plus-slides is what they need, along with space to fill in the gaps. An alternative approach is to make the slides/board material the outline; several of the more effective teachers I had (my high school history teacher and a political science professor at Rose-Hulman) took that approach. But you can’t shovel your script into PowerPoint and expect that to work well, any more than you’d expect that writing it up on the board, or for that matter reading a paper verbatim at a conference would be a good presentation, to work. All this discussion leaves aside the question of teaching anything that involves symbols (chemistry, mathematics, statistics) which I think requires a different approach than bullet-points. In class, mathematics and statistics (and, by extension, social science research methods courses) lend themselves to a combination of “passive” PowerPoint-style presentation and more spontaneous problem-solving and brainstorming; for example, one of my early activities is to have the class try to operationalize (define in terms of a measurable quantity or quality) a concept like “globalization,” which you can’t really do with a static slideshow even though you can define terms like “operationalization” that way. Similarly, while you can step through the process of solving a problem in a slideshow I think it’s more effective to demonstrate how to step through the process on the board. Unfortunately, many classrooms aren’t set up to allow you to present and use a board simultaneously; some of TAMIU‘s lecture halls have a nice design where the projection screen is above the board, so you can write on the board without having to do anything special with the slideshow, but rooms most places are designed for “either-or” which can be a real pain—fiddle with the control system to blank the screen, raise the screen, write on the board, then lower the screen, switch the screen back on. After a few iterations of that in a single class, you’ll never do it again. I freely admit I haven’t figured everything out yet; my current methods slides are pretty good lecture notes but pretty rotten for projection. One of my projects for this summer (postponed from last summer after I learned I wouldn’t be teaching any methods courses this year) is to work on my research methods lectures to incorporate advice from Andrew Gelman’s book so I can lay the groundwork for my plot to take over the world effort to produce a workable, but rigorous, methods curriculum at both the undergraduate and master’s levels for political science, sociology, and (at the grad level) public administration. More on this theme from Laura at 11D, who takes note of some of the more positive technological developments associated with academe. And, another of Burke’s commenters links this hilarious example of what not to do with your slides.

* I use “PowerPoint” as shorthand for the use of a computer-projector based slideshow-style sequential presentation of items associated with a lecture, a technique obviously made famous by the Microsoft software package but also available with many other software packages such as Apple’s Keynote, OpenOffice.org Impress, and several PDF viewers including Adobe Reader, xpdf, and GNOME‘s Evince.
† I’d put the cutoff significantly lower, at around 30–40 students. Beyond that point, one might as well just blow the cap off the class.
‡ By the way, it’s nice to see Michelle’s blog back from haïtus! (Where else would I keep up with current Mexican politics?)

---

Update Added screenshots

---

I spend a lot of time working in front of a screen (many hours in a dimly lit room) and eye fatigue is an issue. A consistent color scheme, especially one which is easy on the eyes, is important and it also helps to have way of doing that where the directives are not all scattered all over my Emacs-lisp setup. Enter Emacs Color Themes, available as the Debian package emacs-goodies. Aided with a HSL color picker, I set around trying to create a dark color theme for Emacs. It does not help that I am blue-green color blind, so subtle variations are often lost on me. I do want to use color contrast to increase productivity, but I also want to avoid the jarring angry fruit salad look, and so I am in the process of crafting a logical color scheme that is high contrast enough for me, without being too unpleasing. In circumstances where there a lot of related faces that can be viewed, for example, the Gnus group buffer, consistent and logical color choices are the only sane option. Gnus groups can be news (bluish) or mail (greenish), have states (large number of unread messages, normal, and empty). The large number unread groups have highest luminosity (appear brighter), and the empty one have lower luminosity (appear greyer), but have the same hue and saturation. Sub states and group priorities are rendered using a color series which has constant luminosity and saturation, and vary in hue by a constant separation so all the related groups have the same brightness ( mail,news / unread,normal,empty ), and a graded selection of foreground colors. It sounds more complicated that it looks. The eye is drawn naturally to the unread groups, and first to the mail, then USENET groups (which is my preference). Similar color variations occur for individual messages in a group; high scoring messages bubble to the top, and have a higher luminosity. This color schema has made me slightly faster at reading mail/USENET. In the message itself, quoted mail messages from different people are color coordinated, with high contrast between citations that are close to each other in the hierarchy, so it is less likely that one misunderstands who said what in a long conversation. The resulting scheme covers programming languages, Gnus, Erc, mail, org-mode, CUA-mode, apt-utils, bbdb, compilation buffers, changelog mode, diff and ediff, eshell, and more. This has allowed me to consolidate all my color directives into a single file, and is in a format that might be usable by others. See the wiki page for details about how to use and switch color themes in Emacs. Enjoy.

While a funeral isn't my favourite reason to visit the family, we all took the opportunity today to get together to celebrate Leif's birthday together, as well as everyone getting together to be there for Henry.

Now I'm at Angie's dad and step-mom's place, about to finally settle into some homework.

We're going to do an open-house for Leif next Sunday at my sister's place. If you'd like to come along to it, email me: jbailey@raspberryginger.com and I'll give you directions.

(And hey, sib. When are you meeting at your place?)

Sorry folks if I haven't gotten ahold of you for getting together. The family plans are trumping everything right now.

I was at two geek events in Zurich this week: At the Google Open Source Jam Zurich on Thursday evening and at the first Webtuesday Hackday on Saturday. Somehow I expected both events to be quite similar, but they weren’t. Google Open Source Jam When I read “Jam” or “Jam Session” I think of Jazz musicians spontaneously playing together. So for me “Open Source Jam” sounded like a hack session where some spontaneous coding is done. But there was no spontaneous collaboration at Open Source Jam at all. It’s just (more or less spontaneous) talks about different topics and chatting. So I was quite disappointed from that event. There were though quite a lot of people I knew from e.g. Webtuesday, Chaostreff or Debian. I even met some people I just knew from IRC until then. Half of the talks were sole propaganda talks though, e.g. for Webtuesday Hackday, OpenExpo and Soaring as a geek sport. Not really wrongly placed talks, but not what I expected in talks at Open Source Jam. The few rooms and floors I saw reminded me very much to IKEA Children’s Paradies, just even more motley. Though it felt all sterile and wasn’t by far as cool as I expected after what I read elsewhere of Google offices. I also think that several of the Google employees showed some contrived friendlyness, and questions I asked e.g. why I have to give them my e-mail address and employer’s name (what do unemployed or self-employed people do?) got answered with answers I do not really believe – like “for security”. A leopard doesn’t change its spots. A data squid probably neither, even not at events labeled with OSS and said to be for the community. I suspect that finding new employees is one of the reasons behind such events at Google. But after my first visit at one of their locations, this company still makes me feel uncomfortable. And I’m even more sure than before that I wouldn’t want to work there. Not sure if I’ll attend the Google Open Source Jam a second time. Webtuesday Hackday Webtuesday Hackday also was not as I expected, but still more close to my expectations: the Webtuesday crowd gathers for hacking instead of having long talks. :-) There were surprisingly many people from outside Zurich, from Munich and Belgium, from Lake Constance and Lausaunne – not only the usual suspects (who were there anyway ;-). The event took place at Liip’s new office. They still look a little bit empty and steril, but all the toys (mini rugby balls, Wii, plush figures on floor lamps) and people around made them very alive. And they had very cool lamps in the form of their company logo in the office. They sure have a good interior designer. :-) Although most participants found time to do some hacking, many found less time than they expected so we hope that we can glue the talks a little bit more together in regards of timing to cause less interruptions of the hacking. The food was also better at Hackday, too, but mostly because we ate outside. ;-) For lunch we were at Lily’s Stomach Supply at Langstrasse (very recommendable!) and in 6he evening we were at Pizzeria Grottino 79 near Helvetiaplatz. Had a Pizza Vesuvio with Gruyère cheese there. Hackday also had a surprise for me: The IRC channel at Hackday was but when I entered the channel there were someone in I didn’t expect there: tklauser aka Tobias Klauser aka tuxedo. Even more surprising, he read about my project idea for Hackday – a semantic feed cache proxy – and liked it, so he decided to come over to Zurich and join the project. We didn’t came that far until Tobias had to leave again, but the progamming language and partially also libraries had been nailed: Ruby and it’s WEBrick framework. After the Hackday I worked on it a few more hours and it now already saves feeds to a cache. The Mercurial repository is at http://noone.org/hg/sfc-proxy. There were several reasons which spoke for using Ruby instead of Perl (my favourite progamming language and the one I’m most experienced in): Ruby brings HTTP and RSS support already in it’s standard classes and Tobias is more experienced in Ruby than Perl. I started to learn Ruby a few years ago to look beyond my own nose and to get my hands dirty on some object-oriented and nice programming language, but I hadn’t found an appropriate project until now, so this was one more reason to not do it in Perl. I also worked on my Debian package of Conkeror during Hackday. It’s already usable and I now use Conkeror as primary web browser on my EeePC, but e.g. the man page is still missing. As soon as I have the minimum in necessary documentation ready I’ll let it upload to Debian Experimental (since its dependency XULRunner 1.9 is also only in Debian Experimental yet). The Mercurial repository for the Debian packaging of Conkeror is at http://noone.org/hg/conkeror/debian Those who were still at Hackday in the evening decided that the Webtuesday Hackday should become a regular institution and should take place approximately every two months, but stay a one day event (for now). I already look forward to the next Webtuesday Hackday.

Laptops are easily lost or stolen and in order to protect your emails, web passwords, encryption keys, etc., you should really think about encrypting (at least) your home directory.

If you happen to have /home on a separate partition already (/dev/hda5 in this example), then it's a really easy process:

1. Copy your home directory to a temporary directory on a different partition:
   

   mkdir /homebackup
   cp -a /home/* /homebackup

2. Encrypt your home partition:
   

   umount /home
   cryptsetup -h sha256 -c aes-cbc-essiv:sha256 -s 256 luksFormat /dev/hda5
   cryptsetup luksOpen /dev/hda5 chome
   mkfs.ext3 -m 0 /dev/mapper/chome

3. Add this line to /etc/crypttab:
   

   chome    /dev/hda5    none    luks,timeout=30

4. Set the home partition to this in /etc/fstab:
   

   /dev/mapper/chome /home ext3 nodev,nosuid,relatime 0 2

5. Copy your home data back into the encrypted partition:
   

   mount /home
   cp -a /homebackup/* /home
   rm -rf /homebackup

That's it. Now to fully secure your laptop against theft, you should think about an encrypted backup strategy for your data...

I’ve been trying to get ipsec to work correctly as a basic VPN between two CentOS 5 systems. I set up the ipsec devices according to the IPSEC section of the RHEL4 security guide [1] (which is the latest documentation available and it seems that nothing has changed since). The documentation is quite good, but getting IPSEC working is really difficult. One thing I really don’t like about IPSEC is the way that it doesn’t have a device, I prefer to have my VPN have it’s own device so that I can easily run tcpdump on the encrypted or the unencrypted stream (or two separate tcpdump sessions) if that’s necessary to discover the cause of the problem). I’ve got IPSEC basically working, and I probably could get it working fully, but it doesn’t seem worth the effort. While fighting with IPSEC at the more complex site (multiple offices which each have multiple networks, and switching paths to route around unreliable networks) I set up an IPSEC installation at a very simple site (two offices within 200 meters both with static public IP addresses, no dynamic routing or anything else complex). The simple site STILL doesn’t work as well as desired, one issue that still concerns me is the arbitrary MTU sizes in some routing gear which (for some reason I haven’t diagnosed yet) lose packets if I have an MTU over 1470 bytes. So today I set up a test network with OpenVPN [2]. It was remarkably simple, the server config file (/etc/openvpn/server.conf) is as follows:
dev tun
ifconfig 10.8.0.1 10.8.0.2
secret static.key
comp-lzo This means that the IP address 10.8.0.1 will be used for the “server” end of the tunnel, and 10.8.0.2 is the “client” end. The secret is stored in /etc/openvpn/static.key (which is the same on both machines and is generated by “openvpn --genkey --secret static.key“). The client config file (/etc/openvpn/client.conf) is as follows:
remote 10.5.0.2
dev tun
ifconfig 10.8.0.2 10.8.0.1
secret static.key
comp-lzo Then I enable IP forwarding on both VPN machines, open UDP port 1194 (the command “lokkit -q -p 1194:udp” does this) and start the daemon on each end. The script /etc/init.d/openvpn (in Dag Wieers package for CentOS 5 - which I believe is the standard script) will just take every file matching /etc/openvpn/*.conf as a service to start. The end result is a point to point link that I can easily route other packets to, I can easily get dynamic routing daemons to add routes pointing to it. Nothing like the IPSEC configuration where the config file needs to have the IP address range hard-coded, I can just add routes whenever I want. This isn’t necessarily going to be the way I deploy it. The documentation notes that a disadvantage is “lack of perfect forward secrecy — key compromise results in total disclosure of previous sessions“. But what gives me confidence is the fact that it was so easy to get it going, if I have problems in adding further features to the configuration it should be easy to debug. As opposed to IPSEC where it’s all complex and if it doesn’t work then it’s all pain. Also I tested this out with four Xen DomU’s, two running as VPN routers and two as clients on separate segments of the VPN. They were connected with three bridge devices. I’ll blog about how to set this up if there is interest.

• [1] http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/security-guide/s1-ipsec-net2net.html


• [2] http://openvpn.net/index.php/documentation/howto.html

Share This

Matt Bottrell has written about some issues related to the acceptable weight of laptops for school use [1]. Matt cites a reference from the Victorian government stating that a school bag should not be heavier than 10% of the body weight of the child who carries it [2]. So the next thing we need to do is to calculate what a student can carry without being at risk of spinal injuries. Firstly we need to determine what children weigh, if we restrict this to the 14+ age range (the older children have more need of computers) then children are almost as heavy as they will be when they are 18 and can carry significantly heavier bags than those in the 10+ age range. Also it seems reasonable to consider the 25th percentile weight (the weight which is exceeded by 75% of children). Of course this means that 25% would be carrying overly heavy bags but it does give us a bit more weight allowance. The 25th percentile weight for white girls in the US is 48Kg [3]. The 25th percentile weight for white boys in the US is also 48Kg [4]. When considering the Australian situation it seems that white children in the US will be most similar (in terms of genetics and diet). The 25th percentile weights at age 18 are 53Kg for girls and 64Kg for boys. So the acceptable bag weights would be 4.8Kg for 14yos, 5.3Kg for 18yo girls, and 6.4Kg for 18yo boys. The next step is to determine the weight carried to school. The weight of one of my laptop bags is almost 1Kg, I think that a school-bag would have a similar weight. When I was at school I recall that the worst days for carrying baggage were when I had PE (Physical Education - sports), the weight of PE gear was a significant portion of the overall weight I carried. I tried to estimate this by weighing a track-suit top, a t-shirt, and a pair of board-shorts (the only shorts I could find at short notice), and it was almost 1Kg. While the board-shorts might weigh more than PE uniform shorts I didn’t include the weight of track-suit pants. Assuming that a female PE uniform has the same weight as a male uniform is the least of my assumptions. The weight of a good pair of sneakers (suitable for playing basketball and other school sports) that is in my size is just over 1Kg. To get a rough estimate of the weight of lunch I put six slices of bread and a small apple in a lunch box and found that it weighed 500g. A real lunch would probably include four slices of bread but the other things would weigh at least as much as the extra two slices. If a drink was included then it could be more than 500g. So the total is 3.5Kg for bare essentials (including PE gear) without including any books! It seems that it would be impossible to stick to the government recommendations for school bag weight if a full set of PE gear is included. Probably the best thing that could be done would be to make a school uniform allow wearing sneakers which removes 1Kg from the overall bag weight. So a bag with lunch and PE gear (minus sneakers) is about 2.5Kg, leaving 2.3Kg for books etc at age 14. As text books for 14yo children are considerably thinner than those for 18yo children, it seems that this might be achievable. Fitting a couple of text books and an EeePC into the 2.3Kg weight budget should be achievable. But fitting a full size laptop (which seems to start at about 1.8Kg) and some text books into a 2.3Kg budget will be a challenge - it might be possible to do that but wouldn’t leave any budget for the random junk that children tend to carry around. For an 18yo girl, the weight budget (after the basics have been deducted) is 2.8Kg, it seems likely that on occasion the weight of year-12 text books will exceed that. Therefore it seems that the only way of avoiding spinal injuries in year-12 girls would be to have text books stored in digital form on a light laptop such as an EeePC. Rather than avoiding the use of laptops because of weight (as some people suggest), laptops with electronic text books should be used to replace traditional text books! An EeePC weighing less than 1Kg will give a significant amount of extra capacity for any other things that need to be carried. If there is little other stuff to be carried then 75% of 18yo girls should be able to carry a full size laptop plus PE gear without risk of back injuries. If digital text books are used then if in any journey two text books (which according to my previous measurements can be as much as 1.6Kg [5]) can be replaced with an EeePC then overall something like 600g is saved (depending on the configuration of the EeePC, if one battery was stored at home and another at school then it could save more than that). It seems that a year 12 girl who has PE and three science subjects scheduled on the same day would be most likely to exceed the recommended weight in the current situation (even without having to carry a spare pair of shoes), and that carrying a laptop with digital text books would be the only way of avoiding back injury. For an 18yo boy the weight budget is 3.9Kg after the basics have been deducted. So if they don’t carry other random stuff in their bag (I probably had 1Kg of random junk in my bag on occasion) then they could carry PE gear, a full sized laptop, AND a full set of text books. It seems to me that there is no situation where children would be unable to have a laptop within the reasonable weight allowance if digital text books were used. The only way that the weight of a laptop could be a problem would be if it was carried in addition to all the text books. One final point, it would be good if books from the Gutenberg project were used for studying English literature, that’s one easy way of reducing weight (and cost). Also it would be good if there was an option for a non-literature based English subject. Knowledge of English literature is of no value to most students. It would be better to teach students how to write while using topics that interest them. Maybe have blogging as an English project. ;)

• [1] http://matt.bottrell.com.au/archives/155-Laptop-clarifications.html


• [2] http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Back_pain_schoolbags?open


• [3] http://www.halls.md/on/girls-weight-w.htm


• [4] http://www.halls.md/chart/boys-weight-w.htm


• [5] http://etbe.coker.com.au/2008/02/18/laptop-vs-book-weight/

Share This

foosel tagged me, whatever that means. Perhaps it’s the English word for “Stöckchen” (German for “small stick”) of which I always wondered how the English blogging part of the blogosphere is calling that kind of coercing blog posts… ;-) So these are the rules:

1. blog a list with your favorite desktop Linux software (as many or few you want)
2. add links to the software project’s websites
3. post these rules
4. tag three other Linux using bloggers

Interestingly splitbrain, who started the thing just calls it “Meme”, but to me memes are the same thing just without duress. ;-) So you want to know about what Linux desktop software I like and use, hmm? Desktop means GUI, doesn’t it? There are only a few GUI application I really use often since, as you probably know, X is primarily a terminal multiplexer and screen resolutions are compared by how many 80×25 xterms with fixed font you can get on one screen without overlapping. ;-) But to be honest: Although I’m more the command line guy hacking cryptic lines into windows with small fonts, there are a few thing where I don’t want to miss X and the GUI applications: For all things web – that means web browser, feed reader, etc. But then there is also a bunch of GUI software I use occasionally or as alternative tool to some text mode or command line software. Web

• Liferea – My favuorite feed reader although it takes ages to start and since a few days also starts crashing, probably since I have configured it to cache up to 1000 items per feed and have subscribed to several hundred feeds. I do not read them all though, but I use them togther with Liferea’s “search all feeds” feature as a Google News replacement. ;-) I though read a lot of feeds in it, since I use it for news, blogs, webcomics and to read missed tweets on Twitter. It organizes the feeds in a tree structure so I can easily group different types of content together.
• Opera – I’m back using Opera as my primary web browser since they offer alpha versions for 64-bit Linux. Initally I started using Opera with version 3.60 on Windows 95 somewhere about 10 years ago and I’ve always come back to it when no current free browser fits my needs. Although it hasn’t an AddOn possibility as Firefox has, I still prefer it over the bloaty and leaky and quite unstable Firefox 2, since it offers nearly every functionality I need (mainly mouse gestures and a flexible tab management), is fast, needs less RAM and is quite stable for an alpha version. And Firefox only offers those features I need via Addons which are often the cause for leaking or crashing. Haven’t tested Firefox 3 yet, but it’s said to be be less bloaty…
• Kazehakase – Formerly I used kazehakase as my primary web browser since I really like its user interface, but the version in Etch is quite slow and seems to have memory leaks. It’s currently the second browser I have always open. But since my browsers always have uptimes in terms of months I don’t need web browsers that are leaking, so I’m thinking about replacing it with something more stable.
• Conkeror – A Gecko 1.9 (i.e. Firefox 3) based web browser completely controllable with the keyboard. And the key bindings are those from Emacs and partially also from the classic text-mode browser Lynx. Will be available in Debian Experimental soon.
• Netsurf looks very promising as it’s a simple and fast browser with it’s own rendering engine and originating on RISC OS. But since I’m a heavy tab user (60 tabs in one window are not really seldom), a browser (yet) without tabs isn’t really that useful for me. But I hope it will get tabs soon.
• Midori – The other upcoming new browser in the Linux world is using Apple’s WebKit (which itself is based on KDE’s KHTML) underneath. Only in Experimental yet (form a Debian point of view :-). Use it on my Debian Sid machine to play around with it.
• Twitux – A simple GTK Twitter client which doesn’t clutter the screen with unnecessary icons or buttons. Just a small menu bar, status bar and the tweets.
• Azureus – In the seldom case where I need to download files via Bittorrent I either use Opera’s builtin client or Azureus. The nice thing about Azureus is that you can get nice graphical as well as textual statistics about all aspects of your downloads.

X / Desktop Environment

• FVWM – My favourite window manager for normal, big or multiple screens. I use it since more than 10 years (twm and tvtwm were its predecessors) and its configuration has evolved since then quite a bit to tinted transparent window frames and title bars, etc. I tried other window managers in between (e.g. Sawfish and GNOME’s own Metacity, each for a month or so and both together GNOME, also played around with KDE on one machine) and I always came back to FVWM. No other window manager is so fast and configurable in regards of keybindings. Handles multiple screen very well and out of the box, too.
• ratpoison – My favourite window manager for small screens (less than about 1024×768, e.g. on my EeePC, on the 8” touchscreen connected to my MicroClient Jr. or on my 1996 ThinkPad 760ED with 133 MHz Pentium 1) since it doesn’t waste screen space for window borders or title bars. It just maximizes all windows by default to screen resolution. You then can manage (split, resize, switch, close, kill) windows as you are used to manage shells and text-mode applications with screen(1). Doesn’t work that well with multiple xrandr managed screens though if they don’t have the same size.
• FLWM – The Fast and Light Window Manager. My favourite low-end but still DAU compatible window manager. Use that on demo and guest accounts, especially on low end machines.
• Synergy – connects displays of other computers (not only X but also even Mac or Windows) with your mouse and keyboard similar to a KVM switch. I use it at work to add my laptop as fourth monitor. ;-)
• trayer – A desktop environmen independend system tray developed by the FVWM Crystal Project. Since I changed from manually editing /etc/network/interface on my laptop each time I came into a new wireless LAN to using GNOME’s Network Manager, I needed a system tray for the nm-applet. Trayer is quite easy to configure using command line options and can handle tinted transparency as I use with FVWM and ATerms. So it fits in perfectly.
• ratmenu and dmenu – For showing generated menus together with ratpoison, I use ratmenu (e.g. as replacement for ratpoison’s non-interactive window list) and dmenu (e.g. as application menu using my own wrapper which generates the menu from some config file). Probably will publish that code once it proved itself stable.

xtrlock – the simplest tool to lock you desktop: The mouse turns into a lock and it only goes away if you enter the right password. No screen saver included though and everyone can see what’s on your desk. I like it though. Use it on low-end machines.

XScreenSaver and Really Slick Screensavers (GLX Port) – Configurable and command controllable screen saver daemon. Favourite modes: GLMatrix and Substrate from XScreenSaver and Lattice Sky Rocket and Hufo’s Smoke from RSS GLX.

xosview – my favourite system monitor since more than a decade.

Terminals

• xterm – there is no better X terminal emulator than the original xterm. I found no other terminal which is so fast, has no problems with text-mode applications (aterms break aptitude’s display), no problems with character set encodings, which can be embedded into other applications and which has a fully working classic Unix cut & paste.
• aterm – When I need a fancy transparent terminal for showing a fancy desktop, I use the AfterStep Terminal Emulator aterm. In that case, the system tray, the window borders, the window’s title bar and the terminal on my desktop have the same fancy tinted transparency.
• yeahconsole – A wrapper around xterm which works like the pulldown console in quake. Good for the short shell usage inbetween. ;-) The other similar pull down consoles I know (KDEish yakuake and GNOMEish tilda) had some issues with focus and keybindings while yeahconsole works just out of the box and showed no problems until now.

Audio and Video

• XMMS and Audacious – If I want to play a single list of files of the same file format or single stream, I usually use the command line tools mpg123 and ogg123. But if I need anything more fancy or more flexible, I prefer the WinAMP clones. Formerly XMMS, nowadays Audacious. Both with some old skin which I use since more than a decade and which I initially used with WinAMP 2 on Windows 95.
• mplayer – no fancy GUI, easily controllable with the keyboard, plays most video file formats I can remember. ;-)

Editing and Developing

• GNU Emacs – I’ve been raised with GNU Emacs and Lisp at university, so I’m quite sticked to that. I usually only start one Emacs instance and connect to it using emacsclient. I also like TRAMP for editing remote files. but I don’t need it that often. On machines, where I don’t want a full blown Emacs installation or under root I prefer GNU Emacs’ little brother GNU Zile (Zile Is a Lossy Emacs), but that’s text-mode and no GUI software.
• OpenOffice.org – I think it’s a really great software, but I use it quite seldom, usually only when I have to open some file in a Microsoft file format. For writing letters, articles, presentations and so I have LaTeX.
• Gnumeric – My preferred spreadsheet application. Although for some purposes I use the OpenOffice.org spreadsheet, usually when Gnumeric has not all necessary features.

Graphics

• xv – Yet another tool I use since more than a decade: No other image viewer is so fast and yet so easy to use with both keyboard and mouse. Open source, but unfortunately not (yet?) free software.
• keyjnote – fancy PDF presenter with a lot of interactive features.
• pdfcube – PDF presenter turning pages as a cube as compiz or Macs do with the desktop.

Chat

• Pidgin – I usually use irssi inside a screen for IRC as well as Jabber and ICQ (via Bitlbee), but I also often have a local Jabber client running which then is Pidgin (formerly known as GAIM).

Other Tools

• Unison – I use it to synchonise the cache and state of my feed reader between laptop and workstation. And I do indeed prefer the GUI version over the text-mode version. I use the text-mode only if I use it from some remote location.
• XKeyCaps – The ideal tool to wreck you keyboard layout. ;-)
• XGnokii – Used it to backup my former Nokia mobile phones, the 6130, the 6210i and the 6310i. Doesn’t work anymore with my new E51, though.
• Sunbird / Iceowl – Not really using it yet, but I plan to use it as my primary calendar tool.
• QEMU / KVM / KQEMU – My favourite desktop hardware emulator. (For servers, I prefer Xen for virtualization.)

Games

• ScummVM
• Planet Penguin Racer / Extreme Tux Racer (all forks of Tux Racer)
• Frozen Bubble
• Battle for Wesnoth
• cuyo, xpuyopuyo, flobopuyo
• Sauerbraten
• PrBoom / Freedoom
• Neverball / Neverputt
• Briquolo
• xfrisk
• Icebreaker
• XBomb

Non-Desktop Applications In case someone wonders about my mail client, Jabber client, IRC client, ICQ client, file manager, notes taking application, shell and versioning system – they’re all command line or text-mode applications:

• E-Mail: mutt
• Chat, Instant Messaging: irssi + Bitlbee + GNU Screen
• File management: coreutils (and sometimes busybox ;-)
• Notes: hnb
• Shell: zsh
• Version control: Subversion (svn), Mercurial (hg)

Who’s next? That’s difficult:

• maol would be interesting, but since a while he just blogs in Jeopardy style, so he would need pack all those programs into the subject of his blog post… No, not a good idea.
• Venty! No, has no active blog anymore.
• Dieter! No, no Linux user.

Hmmm, I think I have to look in a different corner of my circle of friends. Hmm. Ah, now I know:

• dyfa – not really a Linux user, but I guess FreeBSD is ok, too. :-)
• nion – this will be really interesting. He even uses more strange software than I do. ;-)
• alphascorpii – no idea what she prefers (except that it will be available as Debian package ;-)

And no, I don’t expect posts as comprehensive as mine. :-)

Rianna and Annalee Newitz have pretty much said what needs to be said: women do like SF.

Rianna and Annalee Newitz have pretty much said what needs to be said: women do like SF.

I write most of my email (in gmail) and submit most web site content in English, however, a significant portion is also done in Italian. I leave the spell checker in English, because Italian is, in general, quite easy to spell, so that even as a native speaker, a helping hand is occasionally welcome. However, it isn't as if I write Italian perfectly either, so the help there would be nice as well. I find it quite annoying to go change the language in the spell checker option each time, especially when, as an example, I'm responding to email and do 2 in English, one in Italian, another in English, and so on. Ideally, some sort of adaptive technology would be possible, where it figures out what language I'm using, out of a preselected list, after a few words, and starts behaving accordingly. It seems as if there is some discussion, so hopefully a solution won't be too far in the future.

So, the last day of my class on hacking, we are going to spend some time on geeky comics and talking about this pictorial genre. I have started collecting a set of examples that I think are particularly strong and funny reflections of geek/hacker life but I am looking for more. So what are some of your all-time favorite episodes/examples from a comic strip? I am looking for stuff that someone who is not necessarily technically oriented will understand but who will be armed with a fairly broad sense of this world too. Any suggestions would be really appreciated.

So, the last day of my class on hacking, we are going to spend some time on geeky comics and talking about this pictorial genre. I have started collecting a set of examples that I think are particularly strong and funny reflections of geek/hacker life but I am looking for more. So what are some of your all-time favorite episodes/examples from a comic strip? I am looking for stuff that someone who is not necessarily technically oriented will understand but who will be armed with a fairly broad sense of this world too. Any suggestions would be really appreciated.

Someone recently asked me whether it was difficult to fill up my syllabus for my hacker course. I wish. The hard part is actually deciding what to put on as there is too much. This is what I have so far but it will likely change over the summer. I have read a lot of the material but what I most excited about is teaching/reading Richard Sennet’s new book on Craft, which was recently reviewed in depth and in relationship to open source (which Sennet does discuss briefly) by Siva Vaidyanathan in the Chronicle of Higher Education (an article that I co-authored also got some props in the review, which is always nice). The question of what type of activity programming is a complex and deeply interesting one. Its craft-like roots, in part, have to do with the UNIX tradition, something written about humorously by Neal Stephenson and more seriously by other folks like Peter Salus and Chris Kelty in his wonderful rich chapter on UNIX. But craft is not enough to understand coding either. The aesthetics of coding also is a literary affair and the two pieces that capture the aesthetics of code in this light are the following two, also on my syllabus: Black, Maurice
2002 At the Edge of Language: The Art of Code. (a PhD Dissertation from the Department of English at UPenn) Chopra, Samir and Scott Dexter
2007 Free Software and the Aesthetics of Code. In Decoding Liberation. I am excited to review this material, as I need to work through my own chapter on software coding, which is less about the aesthetics of code and more about the tension between collaboration and individualism in production (which obviously maps onto questions of craft and aesthetics but is not quite the same thing).

Someone recently asked me whether it was difficult to fill up my syllabus for my hacker course. I wish. The hard part is actually deciding what to put on as there is too much. This is what I have so far but it will likely change over the summer. I have read a lot of the material but what I most excited about is teaching/reading Richard Sennet’s new book on Craft, which was recently reviewed in depth and in relationship to open source (which Sennet does discuss briefly) by Siva Vaidyanathan in the Chronicle of Higher Education (an article that I co-authored also got some props in the review, which is always nice). The question of what type of activity programming is a complex and deeply interesting one. Its craft-like roots, in part, have to do with the UNIX tradition, something written about humorously by Neal Stephenson and more seriously by other folks like Peter Salus and Chris Kelty in his wonderful rich chapter on UNIX. But craft is not enough to understand coding either. The aesthetics of coding also is a literary affair and the two pieces that capture the aesthetics of code in this light are the following two, also on my syllabus: Black, Maurice
2002 At the Edge of Language: The Art of Code. (a PhD Dissertation from the Department of English at UPenn) Chopra, Samir and Scott Dexter
2007 Free Software and the Aesthetics of Code. In Decoding Liberation. I am excited to review this material, as I need to work through my own chapter on software coding, which is less about the aesthetics of code and more about the tension between collaboration and individualism in production (which obviously maps onto questions of craft and aesthetics but is not quite the same thing).